1 .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
2 .\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
3 .\" <mtk.manpages@gmail.com>
5 .\" %%%LICENSE_START(VERBATIM)
6 .\" Permission is granted to make and distribute verbatim copies of this
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10 .\" Permission is granted to copy and distribute modified versions of this
11 .\" manual under the conditions for verbatim copying, provided that the
12 .\" entire resulting derived work is distributed under the terms of a
13 .\" permission notice identical to this one.
15 .\" Since the Linux kernel and libraries are constantly changing, this
16 .\" manual page may be incorrect or out-of-date. The author(s) assume no
17 .\" responsibility for errors or omissions, or for damages resulting from
18 .\" the use of the information contained herein. The author(s) may not
19 .\" have taken the same level of care in the production of this manual,
20 .\" which is licensed free of charge, as they might when working
23 .\" Formatted or processed versions of this manual, if unaccompanied by
24 .\" the source, must acknowledge the copyright and authors of this work.
27 .\" References consulted:
28 .\" Linux libc source code
29 .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
31 .\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu)
32 .\" Modified 2004-10-31 by aeb
34 .TH LDEXP 3 2013-08-19 "" "Linux Programmer's Manual"
36 ldexp, ldexpf, ldexpl \- multiply floating-point number by integral power of 2
41 .BI "double ldexp(double " x ", int " exp );
43 .BI "float ldexpf(float " x ", int " exp );
45 .BI "long double ldexpl(long double " x ", int " exp );
51 Feature Test Macro Requirements for glibc (see
52 .BR feature_test_macros (7)):
59 _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE ||
60 _POSIX_C_SOURCE\ >=\ 200112L;
69 function returns the result of multiplying the floating-point number
71 by 2 raised to the power
74 On success, these functions return
90 is positive infinity (negative infinity),
91 positive infinity (negative infinity) is returned.
93 If the result underflows,
97 If the result overflows,
99 and the functions return
104 respectively, with a sign the same as
109 for information on how to determine whether an error has occurred
110 when calling these functions.
112 The following errors can occur:
114 Range error, overflow
118 An overflow floating-point exception
122 Range error, underflow
126 An underflow floating-point exception
130 .SS Multithreading (see pthreads(7))
136 functions are thread-safe.
139 The variant returning
148 This page is part of release 3.67 of the Linux
151 A description of the project,
152 information about reporting bugs,
153 and the latest version of this page,
155 \%http://www.kernel.org/doc/man\-pages/.